Introduction

One of the best firs for the east, white fir reaches a mature height of 75 feet or more but is often much smaller in the landscape, 40 to 50 feet. It has a pyramidal shape and horizontal branching with the lower branches drooping toward the ground. The tree should be grown in an open area so the lower branches can touch the ground since it makes an outstanding specimen. When branched to the ground, White fir will cast dense shade, which kills turf grass. The foliage is a wonderful silver-blue that appears much like that of the Colorado blue spruce. White fir may grow one and one-half feet per year with good growing conditions. This tree can take exposure and will withstand heat and drought better than most firs. Abies firma is much more heat-tolerant, has green glossy foliage, and grows even further south into USDA hardiness zone 8.

Figure 1.

Young Abies concolorViolacea: Violacea White Fir

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General Information

Scientific name: Abies concolor

Pronunciation: AY-beez KAWN-kull-er

Common name(s): Violacea White Fir

Family: Pinaceae

USDA hardiness zones: 3A through 7B (Fig. 2)

Origin: native to North America

Uses: Christmas tree; highway median; screen; specimen; Bonsai

Availability: not native to North America

Figure 2.

Range

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Description

Height: 40 to 50 feet

Spread: 15 to 25 feet

Crown uniformity: symmetrical

Crown shape: pyramidal

Crown density: moderate

Growth rate: slow

Texture: fine

Foliage

Leaf arrangement: spiral (Fig. 3)

Leaf type: simple

Leaf margin: entire

Leaf shape: needle-like (filiform)

Leaf venation: parallel

Leaf type and persistence: evergreen, needled evergreen

Leaf blade length: less than 2 inches

Leaf color: silver

Fall color: no color change

Fall characteristic: not showy

Figure 3.

Foliage

[Click thumbnail to enlarge.]

Flower

Flower color: red

Flower characteristics: not showy

Fruit

Fruit shape: cone, elongated

Fruit length: 3 to 6 inches

Fruit covering: dry or hard

Fruit color: brown

Fruit characteristics: does not attract wildlife; not showy; fruit/leaves not a litter problem

Use and Management

White fir transplants well balled-and-burlapped, if properly rootpruned; otherwise it will be hard to transplant. The tree prefers a moist, well-drained loam and dislikes heavy clay or high Ph soils. The root system can adapt to wet or rocky soil conditions by growing close to the surface of the soil. It will not tolerate clay or constantly wet soil. As a Christmas tree, white fir remains fresh and retains its needles for two weeks or more if provided with water. White fir is an excellent substitute for the disease-sensitive Colorado blue spruce, since it is less prone to diseases.

Unfortunately, White Fir is rare in the horticultural trade, but it should be grown and used more often. Another cultivar is Conica which is more dwarf and conically-shaped.

Pests

Generally none are serious, but a few cause some damage. The balsam twig aphid feeds on the new growth of fir, causing distorted needles and deposits of honeydew. Trees can tolerate fairly heavy infestations for a short period of time but are weakened by repeated heavy infestations.

Bagworm builds and lives in a two- to three-inch long sack built from needles and other debris. The insect overwinters as eggs in the sacks of the female. Control by hand-picking the bags in winter.

The more common scale insects infesting fir are oystershell, pine needle, and cottony cushion. These insects are hard to control once inside their shell or waxy coatings. The crawler stage is most easily controlled with appropriate pesticides.

Spider mites in hot areas cause older needles to lose green coloration and become yellowed. The insects are very small and difficult to se, so infestations can become severe before being noticed. This is perhaps the most common problem.

Diseases

Generally none are serious enough to cause concern. Needle and twig blight results in the shriveling and reddening of the new growth. The needles of current seasons growth are curled and dead. Terminal growth and some laterals may be killed.

Pine twig blight is a problem on stressed trees. The fungus will not ordinarily be a problem unless the host plant is weakened. The infection usually begins at the terminal bud near a branch tip. Infection takes place in late summer and the disease progresses down a twig into a node. At times the infection may go into two-year-old wood. Needles on infected branches turn reddish and then die. Cut off and destroy infected twigs.

Several rusts attack firs but are not a problem on landscape trees. The diseases are rarely seen.

Several different fungi cause cankers on the trunks and branches of firs. Cankers are sunken areas in the bark that gradually get larger. When the stem is completely encircled, the part beyond the canker dies. Keep the plants healthy by fertilizing and watering during dry weather. Cankers can be largely prevented by avoiding plant injury.

Root rots caused by several fungi kill roots and rot wood. Little can be done to control the diseases other than to keep trees healthy to prevent disease infection. Maintain tree health by regular fertilization and watering during dry weather.

Footnotes

1.

This document is ENH-161, one of a series of the Environmental Horticulture, UF/IFAS Extension. Original publication date November 1993. Revised December 2006. Reviewed February 2014. Visit the EDIS website at http://edis.ifas.ufl.edu.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.